DK-Technologies MSD100C-Loudness User manual
Trademarks
Adobe and the Adobe Reader are either registered trade arks or trade arks of Adobe Syste s Incorporated in the United States
and/or other countries.
Index
1 INTRODUCTION.............................................................................................................................3
2 About the ITU BS.1770 Loudness Measure ent..............................................................................4
3 The Main Screen................................................................................................................................5
4 Configuring the MSD100C-LOUDNESS.........................................................................................5
5 Operating the MSD100C-LOUDNESS.............................................................................................7
Appendix A Specifications..........................................................................................................8
DK-Technologies A/S
Marielundvej 37D
DK-2730 Herlev - Denmark
Phone +45 44 85 02 55
Fax +45 44 85 02 50
www.dk-technologies.com - [email protected]
1 INTRODUCTION
Congratulations! By purchasing a Master Stereo Display (MSD) fro DK-
Technologies you have decided to actually "see what you hear!" We are certain
that your Master Stereo Display will prove an invaluable tool in your daily work.
The MSD100C-LOUDNESS is a dedicated Loudness eter that easures
loudness according to the ITU BS.1770 reco endation.
The eter has 1 AES-3 input and 1 stereo pair of analogue inputs. It also has 1
VGA output for connection with an external VGA onitor.
1.1 The formatting of this manual
[GATE] – This is a key in a enu that can be pressed.
In the headlines above the sections of this anual are i ages of keys and enu
ite s shown on the LCD screen. These i ages represent the necessary key
order to reach a particular function fro the start-up enu.
2 About the ITU BS.1770 Loudness Measurement
The ITU Reco endation BS.1770 specifies the algorith s to easure audio
progra e loudness. The RLB-LU application i ple ents these algorith s to
display the loudness of a Stereo signal as well as for a Surround Sound Signal.
(The MSD100C-LOUDNESS can only easure Loudness for a stereo signal)
Different working odes of the eter are selectable, including:
· Fast ode for real ti e control of loudness.
· Integrating ode for easuring the loudness of a recorded section or the
co plete recording.
2.1 Applications
There are any applications, where it is necessary to easure and control the
perceived loudness of audio signals.
Exa ples of this includes television and radio broadcast applications, where the
nature and content of the progra e aterial changes frequently. In these
applications the audio content can continually switch between usic, speech
and sound effects. Such changes in the content of the progra e aterial can
result in significant changes in subjective loudness.
Moreover, various for s of dyna ic processing are frequently applied to the
signals, which can have significant effect on the perceived loudness of the
signal.
The atter of subjective loudness is also of great i portance to the usic
industry and in the production of co ercials, where dyna ic range processing
is co only used to axi ize the perceived loudness.
2.2 Loudness Measurements
It is thus well recognized that loudness etering is required for broadcast
applications.
The algorith reco ended by ITU and i ple ented in the RLB-LU application
is based on an extension of the Leq(RLB) algorith to cover stereo and
ultichannel audio signals. In this algorith the Leq is an unweighted ean-
square easure, while the RLB involves a high pass frequency weighting curve
referred to as the Revised Low-frequency B-curve.
Loudness is a perceptual property of an audio signal, when it is reproduced
acoustically. It is a co plex non-linear function of a plitude, frequency and
bandwidth.
Present audio level eters easure the level of audio signals expressed as the
a plitude of the signal - either the r s voltage of an electrical signal or the
sound pressure of an acoustic signal.
This level is an objective property, which is independent of frequency and
bandwidth and is easured linearly in volts, if electrical, or Pascals, if acoustic.
For the purpose of broadcasting, loudness can also be easured as an
electrical property, assu ing a fixed electro-acoustic gain for reproduction. This
assu ption is the basis for the broadcast loudness eter. The reproduction
level, that has been assu ed in the ho e, is 60 dBA. A level found to be typical
for television viewing at ho e.
The RLB-LU application has two ain operating odes for different purposes:
Fast ode (SLIDE) for instantaneous onitoring of the loudness level. This
ode is used in production, post-production and presentation. The progra e
level should be set so that on typical dialogue the eter displays 0 LU on
average.
Integrating ode for a single figure overall loudness. This ode is used for
quality control, ainly at progra e ingestion, progra e e ission and in
post- orte analysis. The single figure output fro this ode allows clear and
una biguous infor ation for loudness atching and gain setting. This ode
akes it easy to secure consistent loudness over different progra es and
short sequences.
3 The Main Screen
Below is the MSD100C-LOUDNESS ain screen.
The ain screen consists of 5 different areas.
Area 1 is a phase correlator that easures the phase relationship between the 2
input channels.
Area 2 is a vector scope also known as a gonio eter. See section
Area 3 is the bar window that shows each channel and a graphical
representation of the loudness easure ent (LU).
Area 4 is nu erical presentation of the loudness easure ent (LU) and a peak
overload indicator.
Area 5 is the soft key enu. This enu will change depending of the different
situations.
4 Configuring the MSD100C-LOUDNESS
The MSD100C-LOUDNESS has two types of configurations - the nor al
configuration and the advanced configuration.
4.1 The normal configuration
The nor al configuration is the configuration of the Gate level and the size of
the sliding window in the Fast ode (Slide ode).
4.1.1 Setting the Gate level
If the audio is under the [GATE] level the calculation of the Loudness will stop
and first start again if one of the channels exceeds the [GATE] level. This is
useful when easuring e.g. golf atches and other types of aterial with
long pauses in the audio.
Use the [] / [] keys to adjust the level. The gate level can be set between
-6dB and -18dB. The default value is -15dB.
123
4
5
4.1.1 The sliding window size
The sliding window size in the fast ode is the length of ti e the loudness
easure ent is calculating the average.
The sliding window size can be changed by pressing the [SLIDE] key. This also
sets the eter in fast ode.
Use the [] / [] keys to adjust the ti e. The ti e can be set between 0
seconds and 9 seconds. The default value is 2 seconds.
4.2 The advanced configuration
Hold the [GATE] key down for about 1 second to enter the Configuration enu.
The s all window on the right hand side is the software version. The software
version is good to know if you need to contact custo er support.
4.2.1 Input Selection
Press the [AES] the change between the analogue and the AES3 input. If the
arker is green the AES3 input is selected. The AES3 input is selected as
default.
4.2.2 The Configuration Wizard
Press the [SETUP] key to enter the configuration wizard.
The first step in the wizard is the configuration of the true peak level. This value
indicates at which level the true peak indicator will turn red. The true peak
indicator is the nu erical presentation of the loudness. Use the [] / [] keys to
adjust the level. The Peak Level can be set between -2dBFs and -9dBFs.
Default value is -2dBFs.
Press the [NEXT] key to continue the wizard.
The second step in the wizard is the configuration of the RLB-LU reference.
The RLB-LU reference is the 0 LU level co pared with dBFs un-weighted.
The level can be tested with a test tone at the sa e level as the RLB-LU REF
setting and a frequency at 300Hz. Use the [] / [] keys to adjust the level. The
RLB-LU Reference can be set between -15dBFs and -24dBFs. The default
value is -20dBFs.
Press the [EXIT] key to finalise the wizard.
4.2.3 Saving the Configuration
Press the [EXIT] key in the configurations enu to save the changes.
5 Operating the MSD100C-LOUDNESS
The MSD100C-LOUDNESS can work in two different odes – in fast ode
(sliding ode) or in integrating ode.
5.1 Fast Mode (Sliding Mode)
The eter is put in to Fast ode by pressing the [SLIDE] key. This also opens
the window size enu as entioned in section 4.1.1.
Press the [EXIT] key to return to the ain enu. Please note that the arked
on the left side of the [SLIDE] key is now green indicating that the eter is in
fast ode.
5.2 Integrating mode
The eter is put in to Integrating ode by pressing the [INTG] key. This will also
reveal the integrating enu. The integrating enu is shown below.
5.2.1 Starting the Integrating measurement
The integrating easure ent is started by pressing the [START]. The nu eric
display and the loudness bar will show the loudness when the easure ent is
running.
5.2.2 Stopping the Integrating measurement
The integrating easure ent is stopped by pressing the [STOP] key. After
stopping the easure ent the result can be seen in the nu eric display and on
the loudness bar.
Appendix A Specifications
A.1 The loudness specification
The MSD100C-LOUDNESS is confor s with the ITU BS.1770 and ITU BS.
1771 reco endations on how to easure loudness.
A.2 Inputs
The MSD100C-LOUDNESS is equipped with 1 AES3 and 1 stereo pair of
analogue inputs.
Digital input
The digital input is equipped with a sa ple rate converter to synchronize the
input to the internal clock.
Sa ple rate range: 30 Hz to 100 kHz.
Internal sa ple rate: 48 kHz.
Bit resolution: 24 bits.
Group delay: axi u 1.75 sec.
Passband ripple: ±0.008 dB.
Total har onic distortion and noise: typical –103 dB at 1 kHz.
Dyna ic range: ore than 120 dB.
No inal input i pedance: 110 oh .
Analogue input
The analogue input is a true transfor er balanced input.
Maxi u input level: +24 dBu.
Frequency range within ±0.3 dB: 30 Hz to 20 kHz.
Passband ripple: ±0,002 dB.
Group delay: less than 0.82 sec.
Dyna ic range, A-weighted: ore than 103 dB.
Crosstalk at 1 kHz: less than –96 dB.
Signal-to-noise ratio: typical 93 dB.
No inal input i pedance: larger than 20 koh .
A.3 Mechanical Specifications
The MSD100C-LOUDNESS is as standard delivered with an U-bracket and a
Base Plate for easy table ount.
Dimensions
Height: 144
Width: 186 (Mounting holes 190 )
Depth: 41
MSD Software Manual Appendix A Specifications
A.4 Pin configurations
A.4.1 Utility Connector with RS232 communication
Utility connector with RS232 co unication.
Connector type 9 Pin Fe ale D-Sub.
*) If connecting to a 9 pin serial port (D-Dub) then pin 2, 3 and 5 must be connected to the same pin numbers on the P .
(RX and TX should not be switched.)
A.4.2 VGA Connector
The MSD100C-LOUDNESS if fitted with a VGA connector for an external
display.
Connector type 15 Pin Fe ale High Density D-Sub.
Signal Name Pin number
RS232 TX 2*)
RS232 RX 3*)
Ground 5*)
Signal Name Pin number
Red 1
Green 2
Blue 3
Ground 5
Ground 6
Ground 7
Ground 8
Ground 10
H-Sync 13
V-Sync 14
Appendix A Specifications MSD Software Manual
A.4.3 Audio and Power Connector
The MSD100C-LOUDNESS is fitted with a 25 pin D-Sub connector for the
audio and power connections A breakout cable to XLR connectors and the
power supply are supplied as standard.
Connector type 25 Pin Fe ale D-Sub.
View from solder side of the 25 pin
MALE D-Sub connector.
Signal Name. Pin number.
Analogue Channel 1 Hot 14
Cold 1
Ground 2
Analogue Channel 2 Hot 15
Cold 3
Ground 16
AES3 Hot 9
Cold 21
Ground 22
Power +Vcc
(15VDC)
25
Ground 12
interstage
Phistersvej 31, 2900 Hellerup, Danmark
Telefon 3946 0000, fax 3946 0040
www.interstage.dk
-pro audio with a smile
Table of contents
